This is my third MBC. I started with a Hallman MBC (90$, from Buschur) which got the job done. I was pushing very little air on a basically stock system. It spooled quickly and spiked about 2psi before leveling off.
However, it was UGLY. It looked like something from Home Depot. So, I replaced it with a TurboXS Standard MBC (70$, Modacar) which was much more attractive. Same performance, looked better, and it was cheaper.
These days, I now push a LOT more air, and 2PSI boost spikes are not acceptable. I had pretty much given up to the fact that I would need an electronic boost controller to get rid of the spikes.
I got a TurboXS High Performance Boost Controller ($129, http://www.turboxs.com) and its AWESOME! It has *two* adjustable valves on it - One ball and spring valve and one bleeder valve.
You set the ball and spring valve tight to maxamize spool up time, and then open the bleeder valve up to get rid of boost spikes. I get FAST spool (with a ball bearing turbo and this mbc, i spool as fast as I did with the T25) and NO BOOST SPIKES AT ALL. Boost shoots up to 1.1 bar and sits there. I LOVE IT! Here is a link to their web site, which has more detailed info about the MBC and some pics.
Just got the TURBOXS HPMBC for Christmas. Have not tried it out yet but it was easy to install even though I had to run to ACE hardware and get some extra vac hose and a T connector.
The directions to put it in say to run off the Wastegate actuator bla bla....but there is another little paragraph saying if running over 15psi, it is recommended to T off the BOV vac line running to the intake man/ blocking off the nipple on the stock boost control(where the restictor is) and block off the nipple on the turbo housing. Is this correct/ better?
Anyone useing th TURBOXS HPMBC, what is the trick with both valves to get the best performance.
Running from the turbo compressor outlet to the MBC means less boost spikes but slower spool up. The reason being.. Pressure is generated AT the compressor housing. If you have the MBC attached there, it will see the pressure increase faster than if you T off of the BOV, because that pressure source is from the intake manifold.
So, T'ing off of the BOV will give you faster spool because it takes longer for the pressure to make its way up to the intake manifold.
I suggest doing it from the Turbo compressor. Boost spike is not acceptable to me, since I want to run as much boost as possible. A 2-3 psi spike puts me at 21-22psi and that is not good.
As for setting the HPBC.. I set it how the instructions indicate. From there only minor adjustment was required. Basically you want the ball and spring valve as closed as possible. Open it up until you are within 1-2PSI of where you want to be, and then open up the bleeder valve until you are just right.
The more closed the ball and spring valve, the faster you will spool up.
Well, i installed it with it set to how the instructions said and I got 20 psi. I turned the Coarse screw clockwise all the way and left the Fine screw alone....still got 16 psi. How is your set lets say if you wanted 10 or 15psi?
by the way, how is yours set up...meaning, do you still have the stock boost controller attached with the 2 vac lines and the electrical hook up? Because I do. I was wondering if that caused any of the high boost or lack of low boost.
I was looking at the standard one (basically due to price) because I am just starting the mods to my car. Since you have had both, do you think that Its worth the extra $60 for the high perf. or would the standard be ok to start with? By the way...do you still have the standard one?
The standard one is fine to start with. It is cheap, good looking, and easy to adjust. All good things to have in an MBC. The difference is that it (and every other mbc besidea the TurboXS High Performance MBC) allows small 1-2 PSI boost spikes.
This is acceptable early on in the game, when you have just started modding, and things like that.. but once you have an upgraded turbo, fuel system, and a fuel management system.. then you dont want the spikes.
Yes, I still have mine but a friend is currently borrowing it. I like to have extra parts around in case something breaks, etc. I still have 2 mbcs, 3 spare bovs, a k&n air filter, and a set of agx adjustable shocks You never know when you are going to need something!
I know this is a strage concept to some people.. but I used the instructions it came with.
Install it using the instructions and go for a drive. See how much boost you are getting. Use the brass adjustment to increase boost to within 1psi of where you want it to be and then use the blue adjustment to fine tune it.
If you add too much boost using the blue adjustment, you will get inconsistent boost levels in the higher gears.
Did you notice this thread was originally started 11 months ago? Woo!
...its good to go back and USE the old threads for info instead of making up new ones that ask the same thing, man your thread has been alive for a long time!
On that note, ProjectGSX, do you notice much change in boost with different temperatures? If i remember correctly you live somewhere out West so i guess nothing too drastic would happen, weather-wise. I live in VA and some mornings will be cold as crap and then it warms up later in the day. I'm wondering if the high performance boost controller would help with its two tuning knobs.. TurboXS is a local company for me, would be cool to check them out but i notice the controller is a bit pricey .
Originally posted by CrankWalk
[BOn that note, ProjectGSX, do you notice much change in boost with different temperatures? If i remember correctly you live somewhere out West so i guess nothing too drastic would happen, weather-wise. I live in VA and some mornings will be cold as crap and then it warms up later in the day. I'm wondering if the high performance boost controller would help with its two tuning knobs.. TurboXS is a local company for me, would be cool to check them out but i notice the controller is a bit pricey . [/B]
I do not notice a fluctuation in boost at different temperatures. I think a big part of boost control has to do with the wastegate, and the wastegate flapper. The XS Engineering turbo I have seems to have a very capable wastegate. The standard issue Mitsu turbo's are a little lacking in that category. Maybe try doing a larger flapper? Or porting the side of the housing so that the flapper can open all the way?
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